Conventionally, industrial robots have been introduced into production systems for various products. As a production system including the industrial robots, a line production system which has a plurality of assembly robots arranged along a conveyor is often adopted, and the production system of this kind is suited for high-volume, low-variety production.
In recent years, product producing style has been gradually shifted from high-volume, low-variety production to low-volume, high-variety production, and correspondingly a cell production system has been gradually adopted. As the cell production system, there has been proposed a system including a plurality of assembly robots arranged adjacent to each other and a plurality of transfer devices each for transferring a product between the assembly robots (for example, see Patent Literature 1).